#include <iostream>
#include <unordered_map>

using namespace std;

int main() {
    unordered_map<char, int> charMap;
    charMap['a'] = 100;
    charMap['b'] = 200;

    // 查找键 'a'
    auto it = charMap.find('a');
    auto it1 = charMap.end();
    if (it != charMap.end()) {
        cout << "键: " << it->first << ", 值: " << it->second << endl;  // 输出: a, 100
    }

    // 查找不存在的键 'c'
    it = charMap.find('c');
    if (it == charMap.end()) {
        cout << "键 'c' 不存在" << endl;
    }

    return 0;
}